JPH0615403Y2 - Fuel cell - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a fuel cell used in the energy sector for directly converting chemical energy of a fuel into electric energy.

[Prior Art] Among fuel cells, a molten carbonate fuel cell has a cathode (electrolyte plate) 1 formed by impregnating a molten carbonate as an electrolyte into a porous material as shown in FIG. Sandwiched between both electrodes (oxygen electrode) 2 and anode (fuel electrode) 3,
One cell I is configured so that power is generated by the potential difference generated between the cathode 2 and the anode 3 by supplying the oxidizing gas to the cathode 2 side and the fuel gas to the anode 3 side, and each cell I Are stacked in multiple layers via the separator 4 to form a fuel cell stack.

In the above conventional fuel cell, when the outer dimensions of both electrodes of the cathode 2 and the anode 3 on both sides of the tile 1 are made smaller than the outer dimensions of the tile 1 and the separator 4, and each cell I is laminated via the separator 4, The peripheral portion of the tile 1 and the peripheral portion of the separator 4 are overlapped with each other so as to prevent gas leakage, and the electrodes of the cathode 2 and the anode 3 are arranged inside the wet seal portion. Further, the periphery of both electrodes is vertically cut and fitted into the gas passage portion of the central portion excluding the peripheral portion of the separator 4.

[Problems to be Solved by the Invention] However, the separator 4 for receiving the electrode also has a vertical surface around the central gas passage forming portion as shown in FIG. When a gap G is formed between the vertical surface and the vertical surfaces at the ends of the electrodes 2 and 3, or when an electrode having a large thickness is used due to the variation of the electrode thickness, the height difference between the separator 4 and the electrode is high. As a result, a gap may occur between the separator 4 and the tile 1. If the gap G between the end surfaces of the electrodes 2 and 3 and the separator 4 is large, the electrolyte of the tile 1 sags in the gap G, and the electrode is thick and the height between the electrodes and the separator 4 is low. If there is a difference, a shearing force acts on the tile 1 at the electrode end position when laminating and applying a tightening force, so that the tile 1 may be easily cracked.

Therefore, in the present invention, even if there is a gap between the electrode end portion and the receiving portion of the separator, or even if there is a height difference between the electrode and the separator, there is a possibility that electrolyte sagging or tile cracking may occur. Is to reduce.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention sandwiches both sides of a tile with both electrodes of a cathode and an anode, and uses an oxidizing gas on the cathode side and a fuel gas on the anode side. In a fuel cell in which cells to be supplied respectively are laminated in multiple layers via a separator, the electrode of the separator having an electrode receiving portion in the central portion of both front and back surfaces to receive both the cathode and anode electrodes. The peripheral portion of the receiving portion is chamfered to form an inclined surface, and the size of both the cathode and anode electrodes is slightly larger than the electrode receiving portion of the separator so that the peripheral portion of both electrodes is Around the cathode and anode electrodes positioned in the electrode receiving portion of the separator by chamfering along the inclined surface to form an inclined surface The fuel cell has a structure in which the inclined surface of the portion is overlapped with the inclined surface around the electrode receiving portion of the separator.

[Operation] Since the inclined surface of the electrode peripheral portion is superposed on the inclined surface of the electrode receiving portion peripheral portion of the separator, even if there is a large gap between the inclined surfaces or there is a difference in height between them, When laminated and tightened, plastic deformation of the electrodes can be expected, the gap can be filled, and the height difference can be made uniform. As a result, it is possible to prevent the electrolyte from dripping into the gap and cracking the electrode.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention in which a tile 1 is sandwiched between electrodes of a cathode 2 and an anode 3 so that an oxidizing gas is supplied to the cathode 2 side and a fuel gas is allowed to flow to the anode 3 side. A cell is laminated in multiple layers with the separator 4 interposed therebetween, and each electrode of the cathode 2 and the anode 3 is positioned in the electrode receiving portion 5 having the gas passage forming unevenness in the central portion except the peripheral portion of the separator 4. In the above configuration, the peripheral portion of the electrode receiving portion 5 of the separator 4 is changed from the conventional vertical surface to the inclined surface A, and the peripheral end faces of the electrodes of the cathode 2 and the anode 3 are also required outward from the conventional vertical surface. Slope B protruding at an angle, and each slope B of electrodes 2 and 3
Are stacked along the inclined surface A of the separator 4.

Now, as shown in FIG. 2, when the gap G between the inclined surfaces B and A which are the mating surfaces of the electrode 3 and the separator 4 becomes large, the electrode 3 is plastically deformed when it is laminated and tightened. Then, as shown in FIG. 3, the gap G can be filled, the gap G can be kept within the allowable value, and the dripping of the electrolyte into the gap can be suppressed to be small. or,
Even when there is a height difference H between the electrode 3 and the separator 4 as shown in FIG. 4, this height difference can be made compatible by the plastic deformation of the cell due to the tightening force of the fuel cell stack, The shearing force acting on the tile 1 can be relaxed by the tightening force, and the tile 1 can be made less likely to crack.

The present invention is not limited to the above-described embodiment. For example, the inclined surface B of the electrode end portion is symmetrically formed on both surfaces as shown in the figure, and only one surface is separated by the separator 4. The inclined surface may be formed by cutting it obliquely along the inclined surface A to form a wedge shape, and the inclined surface of the separator 4 may not be linear but may be curved in an arc shape. Good.

[Effects of the Invention] As described above, according to the fuel cell of the present invention, the peripheral portion of the electrode receiving portion of the separator having the electrode receiving portions at the central portions of both front and back surfaces is formed so as to receive both the cathode and anode electrodes. The chamfered surface is processed into an inclined surface, and the size of both the cathode and anode electrodes is slightly larger than the electrode receiving portion of the separator so that the peripheral portions of both electrodes are along the inclined surface of the separator. A chamfered inclined surface, and the inclined surfaces of the peripheral portions of the cathode and anode electrodes located in the electrode receiving portion of the separator are overlapped with the inclined surface of the separator electrode receiving portion. Therefore, even if there is a large gap in the mating surface between the inclined surface of each peripheral portion of the cathode and the anode and the inclined surface of the peripheral portion of the electrode receiving portion of the separator,
Further, even if there is a difference in height between the electrode and the separator, the electrodes are plastically deformed by laminating and applying a tightening force to fill the gap between the inclined surface of the separator and to make the difference in height even. It becomes possible, and it is possible to obtain an excellent effect that it is possible to make it difficult for the electrolyte to drip into the gap and to prevent the tile from cracking.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part showing an embodiment of the fuel cell of the present invention, FIG. 2 is a sectional view showing a state in which there is a gap between an electrode end and a separator, and FIG. Fig. 4 is a sectional view showing a state in which there is a height difference between an electrode and a separator, Fig. 5 is a sectional view showing a portion of an example of a conventional fuel cell, FIG. 6 is a sectional view showing a state in which a gap is created between the electrode and the separator in FIG. 5 or a height difference is generated. 1 ... Tile, 2 ... Cathode, 3 ... Anode, 4 ...
… Separator, 5 …… Electrode receiving part, A, B …… Sloping surface.

Claims (1)

[Scope of utility model registration request] 1. A cell in which both sides of a tile are sandwiched by both electrodes of a cathode and an anode and an oxidizing gas is supplied to the cathode side and a fuel gas is supplied to the anode side, respectively, are laminated in multiple layers via a separator. In the fuel cell having such a structure, the peripheral portion of the electrode receiving portion of the separator having the electrode receiving portions in the central portions of the front and back surfaces to receive both the cathode and anode electrodes is chamfered to form an inclined surface, And the size of both the cathode and anode electrodes is slightly larger than the electrode receiving portion of the separator, and the peripheral portions of both electrodes are chamfered along the inclined surface of the separator to form an inclined surface, The inclined surfaces of the peripheral portions of both the cathode and anode electrodes located in the electrode receiving portion of the separator are overlapped with the inclined surfaces of the separator around the electrode receiving portion. Fuel cell is characterized in that so as to.